Attachment for dressing grinding wheels



Jan. 8, 1952 E. OLDHAM ATTACHMENT FOR DRESSING GRINDING WHEELS 2 SHEETS-SHEET 1 Filed May 11, 1948 3nventor Jan. 8, 1952 E. OLDHAM 2,531,496

ATTACHMENT FOR DRESSING GRINDING WHEELS Filed May 11, 1948 r 2 SHEETS-SHEET 2 Z? I .9? 7 25/ W5; W

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. dressing operation. In Figure 3 Patented Jan. 8, 1952 ATTACHMENT FOR- D WHE RES SI-NG GRINDING ELS Ernest Oldhain, "St. Catharines, Ontario, Canada;

assignor to General Motors Corporation, Detroit, Mich, a corporation or Delaware Application May 11, 1948, Serial N 0. 26,388

(Cl. lea-1i) 4 Claims. 1 a

This invention has to do with an improved attachment for cutter grinders wherein the grinding wheel may be dressed to provide thereon either a radius or an angular surface (or a combination of both). H

Among the objects of the invention are the following: to provide an improved attachment in which the relationship between the abrasive wheel and work piece is not destroyed by the dressing operation; to provide an improved device of the class described in which the dressing tool may be swung into position readily and, after use, swung out of the way; to provide an improved dressing attachment for abrasive wheels whereby either angles or radii (or a combination or both) may be produced upon the abrasive wheel; and to "provide a means where the prowhich may be moved up and down and also ductivity of the machine on form tool work may i {be increased substantially as compared with devices employed heretofore. Other objects and advantages of the invention will become apparent from the detailed description which follows of a device in accordance with one embodiment of the invention.

In the drawings:

Figure 1 is an elevational view of a tool and cutter grinder on which is mounted an attachment for dressing the abrasive wheel. the dressing tool being shown in operative position for dressing the abrasive wheel.

Figure 2 is a view generally similar to Figure 1 with the grinding wheel head and attachment in a position at right angles with respect to that of Figure 1 and with a dressing tool swung out of contact wlththe abrasive wheel.

Figure 3 'is a view on an enlarged scale as, compared with Figure 1 of the dressing attachment, parts being broken away and in section to show the construction more clearly. In Figure 3 is also shown a test bar and gage block employed in setting up the machine for radial dressing and which are removed during the tool is swung 90' Figure 1.

Figure 4 is a view substantially on line 4-4 in Figure 5.

Figure 5 is a view substantially on line 55 relatively to the position in l in Figure 3.

Referring especially to Figures 1 and 2 there is shown a tool and cutter grindingmachine oi -grindi'ng machine shown includes a base I2 sup porting a work table It movable back andforth also the dressing grinder housing.

rotated. When in located position the column is clamped in position. Any. suitable means, for example the belt drive 21., may be employed for rotating the s indle 22 and grinding wheel 20 mounted thereon. In Figure '2 the colum'nZB and grinder carried thereby are rotated 90 with respect to the position in Figure 1.

The dressing device is fixed in position on the grinder spindle housing 24 by means of a bolt and nut represented by 28 and a 'T-s'lot :29 in the (See especially Figure 3; also see Figure 2.) The dressing device comprises a base 30 contacting housing}! and to which are welded uprights 3'2 and 34. Extending transversely of the uprights 32 and 34 is an assembly consisting of a bottom plate 36 and side plates 38 and ti) welded thereto. (See especially Figure 5; also see Figures 3, 2 and 1.) The plate 36 is slotted at 42. Screws 44 extending through the slot are provided, which, when tightened, secure the plate 36 (and side plates welded thereto) in adjusted position onuprights 32 and 34. The outer portion of the plate 36 is provided on its underside with a dovetail portion 50, the side walls of which are tapered at 52, 54 so that the lowermost portion of the dovetail is of less width than the uppermost portion. The dovetail forms ways which support a slide 58, the upper or male portion 59 of which is in mating relation with the female. By means of feed screw 60 actuated by a wrench or crank, th slide 58 may be moved back and forth in a direction parallel to the axis of the spindle which supports the grinding wheel by an amount indicated by a graduated dial 62.

Immediately below the slide 58 is a member 64. (See especially Figures 3, 4 and 5.) The upper portion 66 of member 64 is circular or dial shape and has graduations 68 thereon representin degrees. An intermediate portion 10 of member 64 is of square shape, while a lower portion 72 has outwardly tapered sides M forming dovetail ways for a second slide. Member 64 is fixed to the first slide!!! by means or screw and parts carried thereby are movable back and.

forth with respect to member 54 by an amount indicated by a graduated dial 82. lower face of slide I6 by means of screws 86 is a housing 88. The housing has an upper, in-, ternal circumferential surface 90, an intermediate internal. circumferential surface 92 of lesser diameter than that of circumferential surface 90, and a lower internal circumferential surface 94 Fixed to the of a greater diameter than either that of the circumferential surfaces at and 92.

Mounted, for rotation within the housing 88 is an assembly consisting of an upper disk I and a lower member I04, the two .being secured together by screws I02. Disk Illll is of somewhat less diameter than that of the upper internal circumferential surface 90 on housing 8350 as to have a loose fit therein. Element I04 has an upper circular-shaped portion I06 in rotatable engagement with the circumferential surface 92 of housin 88 and has, also, a lower circularshaped portion I08 of somewhat lesser diameter than circumferential surface 94510 as to have a rather loose fit therewith. An: annular gasket III! of' felt or other. suitable material forms'a seal between surface 94 and element I08. .By means of a screw H2 in housing 88 (Fig. 3) the members I09 and I04.( and parts carried thereby) may be fixed against rotation in the housing 88. Such condition will exist when the device is used for angular dressing, while-for radius-dressing the screw II 2 is in loosened position and the assembly of members I00 and I04 is rotatable in the housing. At the axis of rotation of member I04 is an opening H4 adapted to engage one end of a test or gage bar I I5 employed in setting up the machine for radius dressing. At the lower end of the test barthere is provided a flat surface I I8 at the central axis of the test bar.

Carried by member I04 is a bracket I of right-angular shape. A horizontal leg of the bracket has an elongated slot I22 of sufficient cross-sectional width that the test bar may pass therethrough without frictionally engaging the sides of the slot. Also passing through the slot I22 is a screw I24 of lesser diameter thanthe width of the lot. A washer I26 is of suflicient dimension to bridge the slot. By means of the slot, screw and washer the bracket maybe moved to different positions of adjustment and, by tightening the screw, secured in adjusted position.

The other and vertically extending leg bf the bracket I20 has an enlarged boss I28 having an opening I30 therein through which passes a holder I32 for a diamond I34 which is adapted to dress the grinding wheel. A screw I 36 fixes the holder I32 in position. In Figure 3 there is shown a gage block I38 having the thickness of they desired radius to be produced on the abrasive wheel. It will be understood/as described above, that the bracket may be moved as necessary to bring the diamond in contact with the gage block and then the screws I24 and I36 t ghtened to secure'the parts' in adjusted position. The test bar and gage block are then removed and the device is then ready for dressing the abrasive wheel. to form the desired radius thereon. In Figure 3 the rotatable parts within housing 88, the bracket I20 carried thereby and the diamond carried by the bracket are shown rotated 90 from that of the dressing position. The parts of the dressing attachment are so proportioned that the diamond point I34 is carried in a horizontal plane through the axis of rotation of the abrasive wheel spindle.

.In setting up the machine the screws 44 are loosened and the welded assembly consisting of bottom" plate 36,-and side plates moved so as to bring the axis of rotation of the member I 04 into approximate alignment with the abrasive wheel. Thisinvolves movement to the right from the position shown in"Figure 3. The screws 44 are then tightened. Finer adjustment of the device may be obtained by adjustment of graduated dial 62. Slide I6 and parts movable thereby may be moved by means of feed screw a desired amount as indicated by graduated dial 82. With the diamond in contact with the rotating abrasive wheel as shown in Figure l, the bracket I20 is oscillated by hand in housing 88 to form the desired radius on the periphery of the abrasive wheel. By means of the feed screw 80, the diamond I34 may be moved inwardly between or during oscillations of the bracket and parts carried thereby wherebyjthe' necessary material may b removed from the grinding wheel;

Should it be desired to use the device for angular dressing an abrasive wheel the rotatable member I04 carrying bracket I20 is locked in position at 90 to that of Figure 3, by means of set screw I I2. The screw 15 is then loosened and the member 64 rotated untilthe desired angle as represented by a suitable graduation 68 on member 64 is in'alignment with a fixed marker line I50 on slide 58. The screw 15 is then tight= ened. The diamond dressing tool is then moved by rotation of dial 82'to bring the same into con tact with the periphery of the rotating grinding wheel to remove material therefrom to thereby form the required angle on the grindin wheel.

From the foregoing it will be seen that an abrasive wheel dressing attachment is provided where in the relationship between the abrasive wheel and work piece to be ground isnot destroyedby the dressing" operation, whereas with previous wheel dressing attachments mounted on the work table I4 the relationship between the Wheel and work was lost each time itwas necessary to re dress the abrasive wheel. The dressin attach= ment permits the. dressing tool to be readily swung into position and, afteruse, swung out of the way. The attachmentpermits either angles or radii to be produced upon the abrasive wheel. Productivity of the machine, on form tool work, is increased substantially as compared with previous arrangements.

While I have shown and described th preferred means in which the principles of the present invention have been embodied, it is to be understood the invention is not to be limited to the particular means shown and described above, but that, in fact, widely different means may be employed in the practice of the broader aspects of my invention.

' Iclaim:

1. An attachment for dressing abrasive wheels in which the abrasive wheel is carried by a spindle in a"; housing having a T.-slot in the upper face thereof, an adjustable support mounted on said housing having .means securing the support to the T 510?) in said housing and having an upper u arm extending parallel to andin a plane above the abrasive wheel spindle, an outer end of said arm having ways thereon for supporting a first slide, a first slide carried by said ways, screw means operably connected to said first slide to move said slide on said ways, a member angularly adjustable with respect to said first slide and carried thereby having ways at the bottom thereof adapted to carry a second slide, said angularly adjustable member having graduations thereon to represent desired degrees of angularity, means securing said angularly adjustable member to said slide in a desired angular relation with respect to said first slide, a second slide carried by the Ways on said angularly adjustable member, screw means operably connected to said second slide to move said second slide on the ways on said angularly adjustable means, a housing carried by said second slide, mechanism rotatably carried by said housing, an adjustable right angular bracket having a horizontal leg and a vertical leg, a diamond tool carried by said vertical leg and located in a horizontal plane through the axis of rotation of the abrasive wheel spindle and means securing the horizontal leg of the bracket in adjusted position so that the diamond tool is'spaced a predetermined distance from the axis of rotation of the mechanism rotatably carried by said housing.

2. A device as in claim 1 in which the mechanism rotatable in the housing has an opening at the axis of rotation thereof supporting a test bar for use in setting up the machine to form a predetermined radius on the abrasive wheel.

3. A device as in claim 1 having means carried by said housing locking the rotatably mounted mechanism in fixed position in said housing.

4. An attachment for dressing abrasive wheels in which the abrasive wheel is carried by a spindle in a housing having a T-slot in the upper face thereof, an adjustable support mounted on said housing having means securing said support to the T-slot in said housing and having an upper arm extending parallel to and in a. plane above the abrasive wheel spindle, and outer end of said arm being slotted and having ways on the lower face thereof for supporting a first slide for movement parallel to the axis of said spindle and above said spindle, a first slide carried by said ways, screw means operably connected to said first slide to move said first slide on said ways, a member angularly adjustable with respect to said first slide and carried thereby having ways at the bottom thereof adapted to carry a seoondslide, said angularly adjustable member having graduations thereon to represent desired degrees of angularmeans securing said angularly adjustable member to the underside of said first slide in a desired angular relation with respect to said first slide including screw mean underneath the elongated slot in said outer end of said arm, a sec- 0nd slide carried by the ways on said angularly adjustable member, screw means operably connected to said second slide to move said second slide on the ways on said angularly adjustable means, a housing carried by said second slide, mechanism rotatably carried by and within said housing, an adjustable right angle bracket having a slotted horizontal leg and a vertical leg, a diamond tool carried by said vertical leg and located in a vertical plane through the axis of rotation of the abrasive wheel spindle and screw means extending through the slot in said horizontal leg securing the same to said rotatable mechanism in adjusted position so that the diamond tool is spaced a predetermined distance from the axis ofrotation of said rotatable mechanism.

ERNEST OLDHAM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,994,386 Dardani Mar. 12, 1935 2,392,668 Helding Jan. 8, 1946 

